In the area of thermal printers, it is well-known that the use of such printers is increasing for certain operations that require a reduction in noise levels and at a reasonable cost. While development work is continually progressing to increase speed of operation with minimum maintenance or care of the equipment, it is seen that improvements are being made to enable operator involvement in the maintaining of such equipment.
In the case of typewriters or like apparatus, it is common practice for the operator to replace the typewriter ribbon at periodic intervals or on an asrequired basis. It is also within the capability of the operator of a printer or like recording equipment to replace the ribbon cassette periodically or as required.
In the case of thermal printers, it is seen that the thermal print head needs to be replaced when the connector pads or runs on the surface of the print head do not operate to provide sharp and precise printing by reason of wear or for other reasons. Print head replacement is also required due to wear and eventual failure of the print element or elements. A flexible flat ribbon-like cable is normally used to connect with the pads or contact surfaces on the print head, and the individual leads or wires of the cable may include end connectors or terminals for contact with the print head pads. Since the end connectors or terminals of the individual leads may be exposed and not protected when the print head is removed, or especially in the case where end connectors or terminals are not utilized, it is necessary to ensure that the terminals or the ends of the leads are not damaged when a print head is reinstalled in the printer.
Representative prior art in the field of thermal print heads includes U.S. Pat. No. 3,958,254, issued to K. Okabe on May 18, 1976, which discloses a thermal printing head supported on a carriage, a flat cable connected to the head, and a plate spring fixed to the carriage to keep the head and the cable in a predetermined position.
U.S. Pat. No. 4,297,039, issued to R. Lees on Oct. 27, 1981, discloses a thermal printer having belt cables with individual conductors connected to printed circuit board conductors and covered with strips of insulating material. A slot through a supporting base element permits one of the belt cables to pass through and beneath the element and to connect to the circuit board.
U.S. Pat. No. 4,350,448, issued to T. Hanagata on Sept. 21, 1982, discloses a thermal head having a contact pattern and a print plate. Contact pieces are soldered to the print plate and are held in grooves in a connector body and are resiliently biased against the contact pattern to effect electrical connection. A flexible electric wire supplies signals to the thermal head.
U.S. Pat. No. 4,399,348, issued to J. J. Bakewell on Aug. 16, 1983, discloses a thermal print head wherein resistive elements are sandwiched between opposing substrates. In one case the elements are recessed to minimize wear, and in another case resistive material is deposited in channels and then ground off to the desired configuration.